Non-Densely Occupied Space Ventilation

I believe that if you uncheck the box towards the top of the form that says " This project contains non-densly occupied spaces," the IEQc1-1 upload and IEQc1-2 table will be removed from the form.

I do not understand the phrase, "Complete Table IEQc1-2 for all mechanical ventilation systems where 20% or more of the design supply airflow serves nondensely-occupied spaces". Can someone please explain it in a simpler form? Are they talking about OA or regular SA?

When a mechanical ventilation system is serving more than 20% of its design supply airflow to non densely occupied spaces (ie offices, open office, etc) then you need to provide "a direct outdoor airflow measurement device capable of measuring the minimum outdoor air intake flow." When calculating the 20% you are using the percent of total SA flow. The airflow measuring devise is to be put on your OA intake. Eg: This is applicable when an AHU is serving 200 CFM to an office space and 800 CFM to a conference room.